Touch Screen with Bacteria Inhibition Layer and Manufacturing Method Thereof

ABSTRACT

The present invention is to provide a touch screen having a bacteria inhibition layer for prohibiting bacteria from growing thereon and a method for manufacturing the same comprising uniformly dispersing particles of nano metal material in a solution to be applied to a surface treatment so that the solution can have a concentration of 20 ppm to 500 ppm; evenly spray coating the solution on a screen of the touch screen; and subjecting the solution coated on the screen of the touch screen to a heat treatment until solvent in the solution is completely evaporated so that the particles of the nano metal material are densely adhered to the screen of the touch screen to form a bacteria inhibition layer thereon.

This application is a continuation of Prior application Ser. No.12/830,453, filed Jul. 6, 2010.

FIELD OF THE INVENTION

The present invention relates to touch screens and more particularly tosuch a touch screen having a bacteria inhibition layer for prohibitingbacteria from growing thereon and a method for manufacturing the same.

BACKGROUND OF THE INVENTION

Electronics and computer technologies have made a significant progressin recent years due to booming of the Internet. Many compact, portableproducts are developed by electronic and computer product designers andmanufacturers for fulfilling the urgent needs of vast consumers.Moreover, a number of significant, revolutionary modifications have beenmade with respect to input component or output component of any one ofthe products due to the consideration of user friendliness. The mostimportant one of the modifications is the development of touch screen.In one aspect, a touch screen as a component of an electronic andcomputer product is adapted to show output characters or graphicsthereon. In another aspect, the touch screen is adapted to sendcharacters or instructions inputted by a user to the electronic andcomputer product. In other words, a touch screen serves as both inputand output devices of an electronic and computer product. After viewingdescription or icons shown on a touch screen of an electronic andcomputer product, a user can point to things on it by touching a buttonor icon on the screen itself so as to operate the electronic andcomputer product. Thus, a user can not only use the electronic andcomputer product conveniently but also operate the same in a userfriendly manner. For a software developer, the electronic and computerproduct provides a flexible, interactive operating platform indeveloping software with user friendly feature. For a consumer, noadditional input device is required to install in the electronic andcomputer product. Thus, expense for buying an input device is saved andthere is no need of preserving space on the electronic and computerproduct.

Recently, many types of electronic and computer products with touchscreen are widely installed in public places such as schools, departmentstores, hospitals, airports, and railroad stations. Any person thus cantouch the screen of a touch screen for information inquiry and guide.For users, touch screen is an input device with simple operation anduser friendly features. Moreover, most problems encountered by people inpublic places can be solved successfully if software installed in atouch screen is well designed. However, bacteria may grow on the touchscreen of an electronic and computer product since it is installed in apublic place for user operation by touching the screen. This is a greatthreat to hygiene and public health. Thus, how to maintain a clean touchscreen of one of many types of electronic and computer productsinstalled in public places is a critical, important issue for authorityof each public place.

In view of the fact that touch screens have become medium ofdisseminating bacteria thus for solving this problem many designers andmanufacturers of electronic and computer products have developed a touchscreen with bacteria inhibition feature in which a bacteria inhibitionlayer is coated on the touch screen. Typically, the bacteria inhibitionlayer is formed of organic material as implemented by designers andmanufacturers of electronic and computer products. Organic materialcoated on a touch screen can inhibit growth of bacteria. However,organic material has a low melting point or boiling point and is easy toevaporate or decompose. Thus, its bacteria inhibition capability onlylasts for a short period of time. Moreover, generally speaking, organicmaterial is toxic. Hence, it is not appropriate to coat organic materialon a product designed to be touched by users. Recently, still somemanufacturers of the art employ popular titanium dioxide as opticalcatalyst for inhibiting growth of bacteria or even destroying the same.Titanium dioxide is subjected to LTV (ultraviolet)-light for beingcatalyzed and thus for destroying bacteria. However, UV-light is veryweak in a room environment. Thus, the desired bacteria inhibition effectis substantially compromised.

Thus, it is desirable to choose a suitable bacteria inhibition materialand provide a novel process of manufacturing touch screens with abacteria inhibition layer in order to contribute significantly to theadvancement of the art.

SUMMARY OF THE INVENTION

After considerable research and experimentation, a touch screen withbacteria inhibition layer and manufacturing method thereof according tothe present invention have been devised so as to overcome the abovedrawback of the prior art.

It is an object of the present invention to provide a method formanufacturing a touch screen comprising uniformly dispersing particlesof nano metal material in a solution to be applied to a surfacetreatment so that the solution can have a concentration of 20 ppm to 500ppm; evenly spray coating the solution on a screen of the touch screen;and subjecting the solution coated on the screen of the touch screen toa heat treatment until solvent in the solution is completely evaporatedso that the particles of the nano metal material are densely adhered tothe screen of the touch screen to form a bacteria inhibition layerthereon.

It is another object of the present invention to subject a screen of atypical touch screen (e.g., IR touch screen, resistive touch screen,capacitive touch screen, or ultrasonic touch screen) to be touched byusers to a prior surface treatment (e.g., hardening treatment,endurability treatment, anti-glare treatment, or anti-reflectiontreatment) and a process of the present invention comprises uniformlydispersing particles of nano metal material in a solution to be appliedto the surface treatment so that the solution can have a concentrationof 20 ppm to 500 ppm; evenly spray coating the solution on the screen ofthe touch screen; and subjecting the solution coated on the screen ofthe touch screen to a heat treatment until the particles of the nanometal material contained are densely adhered to the screen of the touchscreen to form a bacteria inhibition layer thereon.

It is still another object of the present invention to, in preparing thesolution, employ a milling method or an ultrasonic method to uniformlydisperse the particles of the nano metal material in the solution to beapplied to the surface treatment.

It is yet another object of the present invention to employ a spincoating, a dipping coating, a spray coating, or a rolling coating toevenly spray coating the solution on the screen of the touch screen.

It is a further object of the present invention to, in a case of asubstrate for the touch screen being organic material (e.g., PET film),provide the solution for the surface treatment including UV-light resinor thermosetting resin and appropriate solvent such that after evenlyspray coating the solution on a surface of the PET film, it is subjectedto UV lamp radiation or heat treatment depending on types of resin beingused wherein the heat treatment is done in a relative low temperature,for example, between about 50° C. and 100° C.

It is a yet further object of the present invention to, in a case of asubstrate for the touch screen being inorganic material (e.g., glass),provide the solution for the surface treatment including silicate(ester), water, acid, and appropriate solvent such that after evenlyspray coating the solution on a surface of the glass, it is subjected toheat treatment wherein the heat treatment is done in a relative hightemperature, for example, between about 160°0 C. and 200° C.

The above and other objects, features and advantages of the presentinvention will become apparent from the following detailed descriptiontaken with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart depicting a process for manufacturing touch screenwith bacteria inhibition layer according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a process for manufacturing touch screen with abacteria inhibition layer in accordance with the invention isillustrated. The process comprises uniformly dispersing particles ofnano metal material having a diameter in the range of about 1 nm to 100nm in a solution to be applied to surface treatment so that the solutioncan have a concentration of 20 ppm to 500 ppm; evenly spray coating thesolution on a screen of a touch screen; and subjecting the solutioncoated on the touch screen to a heat treatment until solvent in thesolution is completely evaporated. As such, particles of nano metalmaterial are densely adhered to the screen of touch screen to form abacteria inhibition layer thereon. As a result, a touch screen with abacteria inhibition layer is produced. Nano metal material as defined bythe invention means that one has biochemical activation, is able topenetrate cell membrane of a bacteria for damaging enzyme and killingthe same naturally, and has particles having a diameter in the range ofabout 1 nm to 100 nm. Nano metal material may be selected from nano gold(Au), nano silver (Ag), nano copper (Cu), nano zinc (Zn), nano platinum(Pt), or a combination or compound thereof such as nano silver oxide,nano copper oxide, nano zinc oxide, nano silver nitrite, nano coppernitrite, or nano zinc nitrite.

In the invention, the touch screen can be an infrared (IR) one,resistive one, capacitive one, or ultrasonic one depending onmanufacturing process and construction. Screen of the touch screen to betouched by users is subjected to an appropriate surface treatmentdepending on applications. For example, surface treatment can be ahardening treatment, endurability treatment, anti-glare treatment, oranti-reflection treatment. In the invention the process comprisesuniformly dispersing particles of nano metal material in a solution tobe applied to surface treatment so that the solution can have aconcentration of 20 ppm to 500 ppm. Next, the process comprises evenlyspray coating the solution on a screen of a touch screen by employing aconventional coating method such as spin coating, dipping coating, spraycoating, or rolling coating. Next, the process comprises subjecting thesolution coated on the touch screen to a heat treatment until solvent inthe solution is completely evaporated. As such, particles of nano metalmaterial contained in the solution are densely adhered to the screen oftouch screen to form a bacteria inhibition layer thereon. As a result, atouch screen with a bacteria inhibition layer is produced. In the stepof preparing the solution, a milling method or ultrasonic method can beemployed to uniformly disperse particles of nano metal material in thesolution.

Conventionally, substrate for manufacturing the touch screen can beclassified as organic compound and inorganic compound based onproperties of material. For the former, it typically is PET(polyethylene terephthalate) film. For the latter, it typically isglass. Solution for surface treatment and subsequent processes are alsodifferent between the above two different substrates as contemplated bythe invention. In a case of substrate for touch screen being PET film,solution for surface treatment comprises UV-light (or thermosetting)resin and appropriate solvent. After evenly spray coating the solutionon a surface of PET film, it is subjected to UV lamp radiation or heattreatment depending on types of resin being used in which the heattreatment is done in a relative low temperature, for example, betweenabout 50° C. and 100° C. In a case of substrate for touch screen beingglass, solution for surface treatment comprises silicate (ester), water,acid, and appropriate solvent. After evenly spray coating the solutionon a surface of glass, it is subjected to heat treatment only in whichthe heat treatment is done in a relative high temperature, for example,between about 160° C. and 200° C.

A couple of embodiments will be described in detail below for fullydescribing design spirit and operating principle of the invention ascontemplated by the present inventor. Also, an experiment is conductedwith respect to the produced touch screen so as to fully demonstratebacteria inhibition or destroying effect of the invention.

In a preferred embodiment of the invention, a touch screen having glassas substrate is subjected to an anti-glare treatment includingsubjecting particles of nano silver having a diameter in the range ofabout 1 nm to 100 nm to an ultrasonic oscillation in a frequency rangedfrom 10 KHz to 50 KHz for uniformly dispersing the particles of primarystate in an alcoholic solution for preparing a required dispersingsolution; pouring an anti-glare treatment solution consisting ofsilicate (ester) compound and alcohol (or other appropriate solvent)into the dispersing solution; agitating the solution for at least 10minutes until it is uniformly mixed with a pH value indicating acidityand the particles of nano silver having a concentration of about 20 ppmto 500 ppm, evenly spray coating the solution on a screen of a touchscreen; and subjecting screen of the touch screen to a heat treatment ina temperature ranged from about 160° C. to 200° C. for about 30 minutesto 60 minutes until solvent in the solution is completely evaporatedwith the sol-gel reaction being completed. As such, an anti-glare layerwith bacteria inhibition effect is formed on the touch screen. Theanti-glare layer comprises silicone dioxide and nano silver andpreferably has a thickness between about 50 and 5000 angstrom.

In the above embodiment in a case of the touch screen being IR touchscreen, it is possible of uniformly dispersing particles of nano silverweighted 0.1 g and having a diameter of about 10 nm in ethyl alcoholweighted 100 g for preparing a required dispersing solution; addingethyl silicate weighted 900 g in the dispersing solution; pouring thedispersing solution into an anti-glare treatment solution to uniformlymix them until the solution with a pH value 4 is prepared; evenly spraycoating the solution on a glass screen of an IR touch screen; andsubjecting the IR touch screen to a heat treatment in a predeterminedtemperature such as about 180° C. preferably for about 1 hour until ananti-glare layer with bacteria inhibition effect having a thickness ofabout 1000 angstrom is formed on the IR touch screen. In an experimentconducted by the present inventor for comparing the produced IR touchscreen of the invention with a prior IR touch screen without beingsubjected to a bacteria inhibition process. Escherichia coli (E. coli)having a density of 1 million per square centimeter is disseminated onthe screen of each of the above touch screens. The number of E. coliliving on the screen of each of the above touch screens is counted after24 hours. A result shows that the number of E. coli still living on theIR touch screen of the invention is about 99% less than the that atbeginning of the experiment (i.e., 99% reduction. As comparison, thenumber of E. coli still living on the prior IR touch screen withoutbeing subjected to a bacteria inhibition process is about the same asthat at beginning of the experiment. In conclusion, the touch screen ofthe invention can effectively inhibit the growth of bacteria thereon.

In another preferred embodiment of the invention in a case of the touchscreen being a resistive one having its substrate formed of PET film, ina hardening treatment it is possible of uniformly dispersing particlesof nano silver weighted 0.1 g and having a diameter of about 10 nm inmethyl ethyl ketone weighted 100 g for preparing a required dispersingsolution; adding an LTV hardener mainly consisting of polybuteneacrylate monomers weighted 900 g in the dispersing solution; uniformlymixing them; evenly spray coating the solution on screen of theresistive touch screen; subjecting the screen of the resistive touchscreen to an IR heating for about 5 minutes until solvent in thesolution is completely evaporated; and subjecting the resistive touchscreen to be radiated by a UV lamp having a power of 40 W to 60 W untila hardened layer with bacteria inhibition capability haying a thicknessof about several micrometers is formed on the resistive touch screen(i.e., hardening treatment finished). In an experiment conducted by thepresent inventor for comparing the produced resistive touch screen ofthe invention with a prior resistive touch screen without beingsubjected to a bacteria inhibition process, E. coli having a density of1 million per square centimeter is disseminated on the screen of each ofthe above touch screens. The number of E. coli living on the screen ofeach of the above touch screens is counted after 24 hours. A resultshows that the number of E. coli still living on the resistive touchscreen of the invention is about 99% less than that at beginning of theexperiment (i.e., 99% reduction). As comparison, the number of E. colistill living on the prior resistive touch screen without being subjectedto a bacteria inhibition process is about the same as that at beginningof the experiment. In conclusion, the touch screen of the invention caneffectively inhibit the growth of bacteria thereon.

While the invention herein disclosed has been described by means ofspecific embodiments, numerous modifications and variations could bemade thereto by those skilled in the art without departing from thescope and spirit of the invention set forth in the claims.

1-5. (canceled)
 6. A method for manufacturing a resistive touch screen,the method comprising: providing an organic substrate; forming adispersing solution by uniformly dispersing particles of nano-sizedmetal material in a solvent; forming a surface treatment solution;mixing the surface treatment solution with the dispersing solution toform a mixed solution; coating a surface of the organic substrate of theresistive touch screen with the mixed solution; and heating the organicsubstrate of the resistive touch screen until the solvent in the mixedsolution is completely evaporated, and then subjecting the organicsubstrate of the resistive touch screen to an UV radiation, so that theparticles of the nano-sized metal material form a bacteria inhibitionlayer thereon.
 7. The method of claim 6, wherein the organic substrateis formed of PET (polyethylene terephthalate).
 8. The method of claim 6,wherein in the step of forming a dispersing solution, the particles ofnano-sized metal material are weighted 0.1 g dispersed in the solvent.9. The method of claim 8, wherein in the step of forming a dispersingsolution, the solvent comprises methylethylketone that is weighted 100g.
 10. The method of claim 8, wherein in the step of forming adispersing solution, the particles of nano-sized metal material compriseparticles of nano-sized silver (Ag).
 11. The method of claim 6, whereinin the step of forming a surface treatment solution, the surfacetreatment solution comprises a UV hardener.
 12. The method of claim 11,wherein the UV hardener comprises polybutene acrylate monomers that areweighted 900 g.
 13. The method of claim 6, wherein in the step ofsubjecting the organic substrate of the resistive touch screen to an UVradiation, the UV radiation has a power ranged from 40 W to 60 W. 14.The method of claim 6, wherein in the step of forming a dispersingsolution, the particles of the nano-sized metal material are uniformlydispersed in the solvent by a milling method or an ultrasonic vibrationmethod.
 15. The method of claim 6, wherein in the step of coating asurface of the organic substrate of the resistive touch screen with themixed solution, the surface of the organic substrate of the resistivetouch screen is coated with the mixed solution by a spray coatingmethod.
 16. The method of claim 6, wherein the nano-sized metal materialhas a diameter in the range of about 10 nm.
 17. The method of claim 6,wherein in the step of heating the organic substrate of the resistivetouch screen, the organic substrate of the resistive touch screen isheated by an infrared heating.
 18. The method of claim 17, wherein theorganic substrate is heated for 5 minutes by the infrared heating.